Geochemical characteristics and source of crude oil in the Shenhu uplift, Pearl River Mouth Basin, South China Sea.

Autor: Fu, Xiaoyan, Chen, Shijia, He, Xin, You, Junjun, Li, Hui, Lei, Mingzhu
Zdroj: Arabian Journal of Geosciences; Jan2022, Vol. 15 Issue 1, p1-20, 20p
Abstrakt: There is a lack of systematic study on geochemical characteristics and the source of crude oil in Shenhu uplift area of the Pearl River Mouth Basin (PRMB). Under such circumstances, the Rock–Eval, gas chromatography (GC), and gas chromatography-mass spectrometry (GC–MS) experiments were carried out. The results show that the following: (1) The medium-deep lacustrine source rocks of the Wenchang Formation (MWC) in the Wenchang-B depression have the highest organic matter abundance. The shallow lacustrine source rocks of the Wenchang Formation (SWC) in Wenchang-B depression and the shallow lacustrine source rocks of the Enping Formation (SEP) in the Wenchang-A depression have relatively low organic matter abundance, but three sets of hydrocarbons have reached the mature stage and have good hydrocarbon generation potential. (2) The n-alkanes of crude oil in the Shenhu uplift have pre-peak characteristics, and the Pr/Ph > 2.00. The tricyclic terpene (TT) content is relatively low, and C19-C20-C21-C23TT presents a "low–high-low" distribution characteristic. Meanwhile, the content of rearranged sesquiterpanes is higher in bicyclic sesquiterpanes. In addition, ααα20RC27-ααα20RC28-ααα20RC29 regular steranes are "L"-shaped, C30-4 methyl sterane (C30-4MSt)/C29 regular sterane values are between 0.24 and 0.34, and dicadinane (W + T)/C30H values are 1.08–1.61. By comparing these biomarkers with source rocks one by one, it is finally found that the crude oil has the closest genetic relationship with the SEP in well WA4. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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